This invention relates generally to the winding of tape and more particularly to a method and apparatus for using a winding flange guide for improved tape winding.
As the industry moves to higher track densities, higher processing and operating speeds, and thinner, smoother media, the ability to create a high quality wind becomes increasingly critical. This is true whether the strand media is being servowritten, or being used in a cartridge/drive. Current tape processing technology involves using an idler guide to guide the tape as it comes into the pancake and a pack wheel to apply pressure to squeeze out the entrapped air between wraps; higher wind tensions can also help squeeze out the air. The formation of a stable pack depends on one""s ability to achieve asperity to asperity contact between adjacent tape layers, therefore locking the wraps in place on the pancake, before the tape wraps have a chance to slide on the entrapped layers of air. This tape motion can result in scatter winds and popped strands. Popped strands are highly susceptible to edge damage during handling of the pancake and both popped strands and scatter winds result in undesirable tape motion at the recording/servo head. As media becomes smoother, it becomes increasingly difficult to achieve asperity to asperity contact and, consequently, to achieve an acceptable wind or to even wind the tape at all. Increasing the pack force and/or the wind tension are potential ways to overcome this obstacle, but because the industry is moving towards thinner and thinner media, damage to the media as a result of these increased forces becomes an important issue. The present invention will constrain these floating wraps until the entrapped air is expelled and it is possible to move to lower pack forces and wind tensions and still obtain high quality winds, even with thinner, smoother media.
Further problems with packing occur as processing speeds increase. As the tape speed increases, the amount of air that is trapped between layers during winding also increases and pack quality suffers. In this case, the present invention can constrain all of the floating wraps until the entrapped air can be expelled. This permits higher tape processing speeds and, consequently, increased throughput.
Current art for tape cartridges and tape drives uses large flanges to provide an envelope for lateral tape motion (no pack wheel is used). These flanges permit a relatively large amount of lateral tape motion during winding before the tape tension forces out the entrapped air. This often results in scatter winds and subsequent tape motion at the recording head as the pack then unwinds. In fact, the tape will often hit the flanges as it winds/unwinds and this motion is transmitted directly to the head. Because track densities are constantly increasing, any lateral motion at the head becomes very critical because it can lead to servo errors and cartridge failure. By using the present invention in a drive, either with the existing flanges or in place of them, one can reduce and/or eliminate the scatter winds/thrown wraps that result in tape motion at the head and tape edge damage/wear. The present invention can also be used in a cartridge in addition to the flanges or in place of them. If keeping the flanges is desirable (as protection in case the cartridge is dropped, for example), the present invention can be designed to fit inside of the flanges so that it will not interfere with them.
In one embodiment, the invention is a method of winding a tape to form a tape pancake. An end of the tape is attached to a reel. The reel is rotated to wind the tape on the reel and to form a tape pancake. The tape is then guided as it is being wound with a winding flange guide, the winding flange guide having a first flange based from a second flange, the first and second flanges forming an opening less than 0.0012 inches wider than the tape""s width. The winding flange guide is positioned proximate the tape pancake and the first and second flanges extend over the outer wraps of the tape pancake.
In another embodiment, the invention is a take-up reel assembly for receiving a magnetic tape having a thickness and width. The tape is received from a tape source. A rotatable take-up reel has a first end of a magnetic tape operatively connected thereto. A rotatable idler guide is positioned between the take-up reel and the tape source. The magnetic tape forms a tape pancake as the magnetic tape is wound around the take-up reel, and creates a tangent point where the magnetic tape contacts the tape pancake. A winding flange guide has a hub having a first end and a second end. A first flange is operatively connected to the first end of the hub, the first flange having a first guiding surface. A second flange is operatively connected to the second end of the hub, the second flange having a second guiding surface. The winding flange guide is positioned to contact the tape pancake at or after the point of tangency, wherein the tape pancake is guided between the first and second guiding surfaces.
In another embodiment, the invention is a tape cartridge having a housing. A magnetic tape, having a thickness and a width, has a first end operatively connected to a rotatable take-up reel, the reel operatively connected to the housing. A rotatable idler guide is operatively connected to the housing. The magnetic tape forms a tape pancake as the magnetic tape is wound around the take-up reel, and creates a tangent point where the magnetic tape contacts the tape pancake. A winding flange guide has a hub having a first end and a second end. The first flange is operatively connected to the first end of the hub, the first flange having a first guiding surface. The second flange is operatively connected to the second end of the hub, the second flange having a second guiding surface. The winding flange guide is positioned to contact the tape pancake at or after the point of tangency, wherein the tape pancake is guided between the first and second guiding surfaces. The guide is operatively connected to the housing and biased to contact the tape pancake.
In another embodiment, the invention is a take-up reel assembly for receiving a magnetic tape having a thickness and a width. The tape is received by the take-up reel from a tape source. The reel assembly includes a mounting member and a rotatable take-up reel, the magnetic tape having a first end operatively connected to the take-up reel, the take-up reel operatively connected to the mounting member. A rotatable idler guide is positioned between the take-up reel and tape source, the idler operatively connected to the mounting member. A magnetic tape forms a tape pancake as the magnetic tape is wound around the take-up reel, and creates a tangent point where the magnetic tape contacts the tape pancake. A winding flange guide is operatively connected to the mounting member. The guide includes a hub having a first end and a second end. A first flange is operatively connected to the first end of the hub, the first flange having a guiding surface. A second flange is operatively connected to the second end of the hub, the second flange having a second guiding surface. The winding flange guide is positioned to contact the tape pancake at or after the point of tangency, wherein the tape pancake is guided between the first and second guiding surfaces. The first flange and second flange have a length that is less than 100 times the thickness of the magnetic tape and the length of the first and second flanges is greater than 10 times the thickness of the tape media.
In another embodiment, the invention is a tape drive having a housing. A magnetic tape having a thickness and a width has a first end operatively connected to a rotatable take-up reel, the reel operatively connected to the housing. A rotatable idler guide is positioned between the take-up reel and tape source, the idler guide operatively connected to the housing. The magnetic tape forms a tape pancake as the magnetic tape is wound around the take-up reel and creates a tangent point where the magnetic tape contacts the tape pancake. A winding flange guide has a hub having a first and second end. A first flange is operatively connected to the first end of the hub, the first flange having a first guiding surface. The second flange is operatively connected to the second end of the hub, the second flange having a second guiding surface. The winding flange guide is positioned to contact the tape pancake at or after the point of tangency, wherein the tape pancake is guided between the first and second guiding surfaces. The guide is operatively connected to the housing and biased to contact the tape pancake. The housing has a section to receive a tape cartridge on which the magnetic tape is stored.
In another embodiment, the invention is a servo writer having a mounting member. A rewind plate assembly is slidably mounted to the mounting member. A take-up reel is rotatably mounted to the mounting member. A rotatable idler guide is operatively connected to the mounting member. The magnetic tape forms a tape pancake as the tape is wound around the take-up reel and creates a tangent point where the magnetic tape contacts the tape pancake. A winding flange guide is operatively connected to the rewind assembly plate. The guide includes a hub having a first end and a second end. A first flange is operatively connected to the first end of the hub, the first flange having a first guiding surface. The second flange is operatively connected to the second end of the hub, the second flange having a second guiding surface. The winding flange guide is positioned to contact the tape pancake at or after the point of tangency, wherein the tape pancake is guided between the first and second guiding surfaces.